a. Field of the Invention
The present invention relates generally to medical devices and more particularly to a family of electrophysiology (EP) catheters with a mechanism for omni-directional deflection of a catheter shaft which mechanism is free of so-called pull wires or other mechanical tensioning components.
b. Background Art
Many medical procedures require the introduction of specialized medical devices in and around the human heart. Such specialized devices include introducers, access sheaths, catheters, dilators, needles, and the like. Such devices may be used to access areas of the heart, such as the atria or ventricles, and have been used in such medical procedures for a number of years. During such a procedure, a physician typically maneuvers the device through the vasculature of a patient. Accordingly, such devices preferably exhibit at least some degree of flexibility to allow for such maneuvering. To achieve flexibility, pull wires may be provided, which are used to control the movement and relative curvature of the devices. Pull wires extend generally along the length of the device (i.e., typically within an outer wall), and may be coupled at the distal end to a pull ring and at the proximal end to a control mechanism. A typical control mechanism may be, for example, a user-actuated knob that can be rotated, which in turn “pulls” one or more of the pull wires in a predetermined fashion, resulting in the desired deflection.
Repeated deflections of the catheter distal end through use of the pull wires, however, may cause a compression of the catheter shaft at the distal end. Compression causes the catheter shaft to lose its original shape, dimension (e.g., axial dimension), and deflectability. In addition, entanglements of the pull wires during catheter deflection are also known to occur, which may limit the functionality and operability of the device. Moreover, bi-directional deflection of a catheter distal end portion has conventionally been implemented using a pair of diametrically opposing pull wires in combination with manual rotation of the entire catheter shaft about a main axis. Also, applicant is aware of catheter shafts housing four discrete pull wires each oriented at 90 degrees from adjacent wires. However, in some circumstances, it may be undesirable to allow rotation of the outer catheter shaft, for example, when a directional energy delivery/sensing component or an imaging sensor or the like is coupled to a portion of the distal end and thus maintaining or having consistent orientation of such components or sensors is paramount for precise operation.
There is therefore a need for a catheter that minimizes or eliminates one or more of the problems set forth above.